Reference values for high-density lipoprotein particle size and volume by dynamic light scattering in a Brazilian population sample and their relationships with metabolic parameters.

BACKGROUND: Current data indicate that the size of high-density lipoprotein (HDL) may be considered an important marker for cardiovascular disease risk. We established reference values of mean HDL size and volume in an asymptomatic representative Brazilian population sample (n=590) and their associations with metabolic parameters by gender. METHODS: Size and volume were determined in HDL isolated from plasma by polyethyleneglycol precipitation of apoB-containing lipoproteins and measured using the dynamic light scattering (DLS) technique. RESULTS: Although the gender and age distributions agreed with other studies, the mean HDL size reference value was slightly lower than in some other populations. Both HDL size and volume were influenced by gender and varied according to age. HDL size was associated with age and HDL-C (total population); non- white ethnicity and CETP inversely (females); HDL-C and PLTP mass (males). On the other hand, HDL volume was determined only by HDL-C (total population and in both genders) and by PLTP mass (males). CONCLUSIONS: The reference values for mean HDL size and volume using the DLS technique were established in an asymptomatic and representative Brazilian population sample, as well as their related metabolic factors. HDL-C was a major determinant of HDL size and volume, which were differently modulated in females and in males.

Mediterranean diet supplemented with nuts reduces waist circumference and shifts lipoprotein subfractions to a less atherogenic pattern in subjects at high cardiovascular risk.

OBJECTIVE: The PREDIMED trial showed that Mediterranean diets supplemented with either extra-virgin olive oil or nuts reduced incident cardiovascular events compared to a control diet. Consumption of both supplemental foods has been associated with reduced LDL-cholesterol, but it is unknown whether they can shift lipoprotein subfractions to a less atherogenic pattern. We investigated changes in adiposity and lipoprotein subfractions after consumption of the PREDIMED diets. METHODS: In a PREDIMED sub-cohort (n = 169), lipoprotein subclasses (particle concentrations and size) were determined by nuclear magnetic resonance spectroscopy at baseline and after intervention for 1 year. RESULTS: Participants allocated to the Mediterranean diet supplemented with nuts showed significant reductions from baseline of waist circumference (mean [95% CI]; -5 cm [-7; -3]) and concentrations of medium-small (-27 nmol/l [-46; -8]) and very small LDL (-111 nmol/l [-180; -42]); decreased LDL particle number (a nuclear magnetic resonance-specific measurement) (-98 nmol/l [-184; -11]); and an increase of large LDL concentrations (54 nmol/l [18; 90]), with a net increase (0.2 nmol/l [0.1; 0.4]) of LDL size. The Mediterranean diets with olive oil and nuts increased large HDL concentrations (0.6 µM [0.0; 1.1] and 1.0 µM [0.4; 1.5], respectively). Compared to the other two intervention groups, participants in the nut-enriched diet showed significantly reduced waist circumference (p ≤ 0.006, both) and increased LDL size (p < 0.05, both). CONCLUSION: Lipoprotein subfractions are shifted to a less atherogenic pattern by consumption of Mediterranean diets enriched with nuts. The results contribute mechanistic evidence for the reduction of cardiovascular events observed in the PREDIMED trial.